Attach tracing (kprobe, trampoline) to internal kernel functions according options used to compile kernel.
This collector is only supported on the following platforms:
Linux
This collector supports collecting metrics from multiple instances of this integration, including remote instances.
The plugin needs setuid because it loads data inside kernel. Netada sets necessary permission during installation time.
Default Behavior
Auto-Detection
The plugin checks kernel compilation flags (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT) and presence of BTF files to decide which eBPF program will be attached.
Limits
The default configuration for this integration does not impose any limits on data collection.
Performance Impact
This thread will add overhead every time that an internal kernel function monitored by this thread is called. The estimated additional period of time is between 90-200ms per call on kernels that do not have BTF technology.
Setup
Prerequisites
Compile kernel
Check if your kernel was compiled with necessary options (CONFIG_KPROBES, CONFIG_BPF, CONFIG_BPF_SYSCALL, CONFIG_BPF_JIT) in /proc/config.gz or inside /boot/config file. Some cited names can be different accoring preferences of Linux distributions.
When you do not have options set, it is necessary to get the kernel source code from https://kernel.org or a kernel package from your distribution, this last is preferred. The kernel compilation has a well definedd pattern, but distributions can deliver their configuration files
with different names.
Now follow steps:
Copy the configuration file to /usr/src/linux/.config.
Select the necessary options: make oldconfig
Compile your kernel image: make bzImage
Compile your modules: make modules
Copy your new kernel image for boot loader directory
Install the new modules: make modules_install
Generate an initial ramdisk image (initrd) if it is necessary.
Update your boot loader
Configuration
Options
All options are defined inside section [global].
Option
Description
Default
Required
update every
Data collection frequency.
5
no
ebpf load mode
Define whether plugin will monitor the call (entry) for the functions or it will also monitor the return (return).
entry
no
apps
Enable or disable integration with apps.plugin
no
no
cgroups
Enable or disable integration with cgroup.plugin
no
no
pid table size
Number of elements stored inside hash tables used to monitor calls per PID.
32768
no
ebpf type format
Define the file type to load an eBPF program. Three options are available: legacy (Attach only kprobe), co-re (Plugin tries to use trampoline when available), and auto (plugin check OS configuration before to load).
auto
no
ebpf co-re tracing
Select the attach method used by plugin when co-re is defined in previous option. Two options are available: trampoline (Option with lowest overhead), and probe (the same of legacy code).
trampoline
no
maps per core
Define how plugin will load their hash maps. When enabled (yes) plugin will load one hash table per core, instead to have centralized information.
yes
no
lifetime
Set default lifetime for thread when enabled by cloud.
300
no
via File
The configuration file name for this integration is ebpf.d/vfs.conf.
The file format is a modified INI syntax. The general structure is:
[section1]option1=some value
option2 = some other value[section2]option3=some third value
